EP2617522B1 - Device for finely processing a peripheral area of the workpiece fixed in an eccentric manner to a peripheral area of a workpiece - Google Patents

Description

The invention relates to a device for fine machining of a workpiece peripheral surface, in particular a crank bearing of a crankshaft, eccentrically arranged with respect to a workpiece axis of a workpiece, with a rotary drive device for rotationally driving the workpiece about the workpiece axis, with a pressure device for pressing a finishing tool against the workpiece peripheral surface, and with a bearing device for the storage of the pressing device on a frame.

From the DE 10 2007 059 926 A1 a device is known for machining peripheral surfaces of substantially rotationally symmetrical workpiece sections on workpieces, such as camshafts and crankshafts, which have a workpiece axis and a plurality of offset along the workpiece axis Have workpiece sections. The DE 10 2007 059 926 A1 proposes to provide with respect to the workpiece axis to each other angularly offset Finisheinheiten. This should allow a space-saving and structurally simplified arrangement of parallel to the workpiece axis juxtaposed finishing units.

The present invention has for its object to provide a device of the type mentioned, which allows high quality requirements and at the same time economic fine machining of a workpiece.

This object is achieved in a device of the aforementioned type according to the invention that a Kraftbeaufschlagungseinrichtung is provided, which exerts a conditional on the rotation of the workpiece between two reversing layers and herbewegendes bearing part of the bearing device braking and / or acceleration forces.

The device according to the invention makes it possible to reduce the inertia forces occurring during the fine machining of a workpiece or even to avoid them at least as far as possible. Thus, the contact forces acting in the contact area between the finishing tool and the workpiece can be evened out, thus even the removal rates are made uniform and the machining quality can be improved. The braking forces make it possible to decelerate the reciprocating bearing part of the bearing device before reaching a reversing position. The acceleration forces make it possible to drive the bearing part in the direction of the other reversal position during or after reaching a reversal position. As a result, a significant reassurance of the storage facility reached. This reassurance also has the consequence that the rotary drive device provided for the rotary drive of the workpiece does not have to generate correspondingly varying drive torques for the reciprocating movement of the bearing part in order to ensure a constant rotation of the workpiece. Rather, the rotary drive device only has to apply a largely constant drive torque. This also means that the workpiece peripheral surface to be machined has higher roundness accuracies. In addition, it is possible to increase the rotational drive speed of the workpiece, so that the machining quality is increased, higher material removal rates are achieved and the finishing of a workpiece takes less time.

It is preferred if the force application device exerts an acceleration force directed in the direction of the other reversal position on the bearing part, at least in one of the reversal positions of the bearing part. This allows compensation of the inertia force occurring in the reverse position, in particular in the case of a bearing part which moves in the vertical direction with respect to the direction of gravity and is preferably acted upon by an acceleration force at least in the lower reversal position.

In particular, it is preferred if the force-applying device exerts on the bearing part at least in each of two reversal positions of the bearing part an acceleration force directed in the direction of the other reversing position. This allows compensation of the inertia forces in both reversal positions.

According to a development of the invention, it is proposed that the force application device with the bearing part Braking and / or acceleration forces applied when the bearing part is located in an intermediate position arranged between the reversal positions. In this way, a braking of the bearing part and / or an acceleration of the bearing part not only punctually in the reversal positions, but additionally or alternatively, also in the intermediate layers, so that a particularly strong reassurance of the bearing device is achieved. In addition, the braking and / or acceleration forces "smoother" (in the sense of temporally steady) can be introduced into the bearing part.

According to a preferred embodiment of the invention it is provided that the Kraftbeaufschlagungseinrichtung comprises an energy store, which in the course of the movement of the bearing part from a first reversal position in a second reversal position is rechargeable and dischargeable in the opposite direction. The charging of the energy accumulator may in particular be accompanied by the exertion of braking forces on the bearing part. The discharge of the energy store is associated in particular with the exertion of acceleration forces on the bearing part and thus with a support of the movement of the bearing part from the first reversal position to the second reversal position. An energy store has the advantage that the kinetic energy of the bearing part can be used to generate the braking and / or acceleration forces, so that the rotary drive requires less energy for the rotary drive of the tool. An in principle conceivable, per se advantageous and subsequently explained "active" Kraftbeaufschlagungseinrichtung comprising an external power supply can be omitted when using an energy storage.

Preferably, at least two energy stores are provided, which can be charged in opposite directions of movement of the bearing part and thus in each opposite directions of movement of the bearing part can be discharged.

As energy storage mechanically or pneumatically effective spring elements can be used in an advantageous manner. During charging of such spring elements, these braking forces cause the bearing part to decelerate. During the unloading of the spring elements, the energy stored in the spring elements is released and causes an acceleration of the bearing part.

Advantageously, the force application device comprises at least one cylinder / piston unit. Such a unit is particularly well suited for the integration of energy storage described above. A cylinder / piston unit can also be used as a power transmission device, which derives the inertia forces of the bearing part in an environment of the bearing part to compensate for the inertia forces there, for example by means of energy storage, in particular in the form of spring elements, or by means of active force generating elements, which pneumatically, hydraulically, mechanically or electrically.

A particularly simple derivation of inertia forces in an environment of the bearing part results when the interior of a cylinder of a cylinder / piston unit is fluidly connected to an additional volume.

Furthermore, it is advantageous if a supply device for pressurizing the interior of a cylinder and / or an additional volume connected to the interior is provided with a presettable, in particular variable, fluid pressure. Such a supply device can be fed, for example, by means of compressed air. The change in the fluid pressure can be used to set a spring rate of the force applying device and allows easy adjustment of the amount of braking and / or acceleration force.

It is possible to set up the force application device in such a way that it provides a predefinable maximum force for a specific rotational speed of the workpiece and a specific distance between the workpiece peripheral surface and the workpiece axis of the workpiece and for a certain mass of the bearing part and the pressing device and optionally the fine machining tool. However, for a simple adaptation of the device, in particular for different rotational speeds and different distances between the workpiece peripheral surface and the workpiece axis of the workpiece, it is advantageous if a control device for controlling the amount and / or the direction and / or the time course of a on the bearing part acting braking and / or acceleration force is provided. In this way, the device can be adapted quickly and easily to different workpiece geometries and production parameters.

Advantageously, a device for detecting the position of the bearing part is provided. In conjunction with a control device described above is hereby a Particularly simple control of Kraftbeaufschlagungseinrichtung possible.

For a defined movement of the bearing part, it is advantageous if this is guided on a linear guide.

The linear guide is pivotally mounted, for example by means of a pivoting part relative to the frame. In this way, the bearing part in a direction transverse to its reciprocating motion to understand the movements of the workpiece peripheral surface to be machined.

Alternatively, it is possible that the linear guide is arranged on a carriage, which is mounted transversely to the guide axis of the linear guide in a direction transversely, in particular vertically, on the frame. Such a construction may also be referred to as a "cross slide".

According to a further embodiment of the invention, a further force application device is provided for the compensation of mass inertial forces, which arise due to a movement of the bearing part about a pivot axis or due to the movement of the bearing part in a direction transverse to the guide axis of the linear guide. (However, such Kraftbeaufschlagungseinrichtung can also be used when a Kraftbeaufschlagungseinrichtung for generating braking and / or acceleration forces on the between two reversing positions reciprocating bearing part is not provided.)

The device described above is suitable for bearing parts, which reciprocate substantially in the horizontal direction. The above device but can also be used for bearing parts, which reciprocate in the vertical direction.

In the event that the bearing part along a relative to the direction of gravity vertical axis between the reversal positions is movable, it is advantageous if a compensation device is provided which generates at least partially a vertically upwardly acting holding force, the amount of the weight of the pressing device, the Bearing parts and the finishing tool (for example, a finishing stone or run on a tape guide finishing tape) corresponds. In this way, a compensation of at least a part of the weight of said parts of the device is possible.

Alternatively or additionally, the holding force can be generated at least partially by the force application device. In this way, a compensation of at least a part of the weight of said parts of the device is possible. In the event that the force application device generates at least part of the holding force, it is particularly preferred if the holding force exerted on the bearing part by the force application device is adjustable. In the case of using a spring to produce at least part of the holding force, such adjustability can be achieved by changing the spring bias (in the case of a mechanical spring by changing the position of spring stops, in the case of a pneumatic spring by changing the gas pressure).

In the event that the Kraftbeaufschlagungseinrichtung allows the setting of a holding force, the same Kraftbeaufschlagungseinrichtungen be used for horizontally movable bearing parts and for vertically movable and weight-compensated bearing parts. As a result, the benefits of a modular system come into play.

In the context of the invention, the finishing tool can be a polishing, lapping, grinding or roller burnishing tool.

In particular, the finishing tool is a finishing tool, which cooperates with the pressing device and has a wear-effective, abrasive active surface. For example, it is a finishing tool in the form of a finishing stone, which is attached to the pressing device. However, the finishing tool can also be a finishing belt, which is preferably pressed against the workpiece circumferential surface by means of a pressing shell of the pressing device.

In particular, in the case where the fine machining tool is a finishing tool, it is preferred if the device comprises an oscillation drive for acting on the workpiece with an oscillation movement parallel to the workpiece axis, so that a cross-cut structure characteristic of the finishing method can be generated by means of the device.

Further features and advantages of the invention are the subject of the following description and the drawings of preferred embodiments.

Fig. 1

eine perspektivische Darstellung einer Ausführungsform einer Vorrichtung zur finishenden Feinbearbeitung eines Werkstücks;

Fig. 2

eine Seitenansicht eines Teils der Vorrichtung gemäß Fig. 1, umfassend ein Feinbearbeitungswerkzeug in Form eines Finishwerkzeugs, eine Andrückeinrichtung und eine Lagereinrichtung;

Fig. 3

eine der Fig. 2 entsprechende Seitenansicht in einer im Bereich einer Kraftbeaufschlagungseinrichtung ausbruchsweise geschnittenen Darstellung in einer 0° entsprechenden Ausgangslage einer Werkstückumfangsfläche eines Werkstücks;

Fig. 4

eine der Fig. 3 entsprechende Seitenansicht in einer um 90° relativ zu der Ausgangslage verdrehten Lage des Werkstücks;

Fig. 5

eine der Fig. 3 entsprechende Seitenansicht in einer um 180° relativ zu der Ausgangslage verdrehten Lage des Werkstücks;

Fig. 6

eine der Fig. 3 entsprechende Seitenansicht in einer um 270° relativ zu der Ausgangslage verdrehten Lage des Werkstücks;

Fig. 7

eine der Fig. 3 entsprechende Seitenansicht bei Erweiterung der Vorrichtung mit einer Einrichtung zur Erfassung der Lage eines Lagerteils der Lagereinrichtung;

Fig. 8

eine der Fig. 3 entsprechende Seitenansicht bei Verwendung von mechanischen Federn als Krafterzeugungselemente und Energiespeicher;

Fig. 9

eine der Fig. 3 entsprechende Seitenansicht bei Verwendung von mit Zylinder-/Kolbeneinheiten fluidwirksam verbundenen Zusatzvolumina;

Fig. 10

eine der Fig. 3 entsprechende Seitenansicht bei Verwendung einer hydraulisch angesteuerten Gasfeder;

Fig. 11

eine der Fig. 3 entsprechende Seitenansicht bei Verwendung einer hydraulisch angesteuerten mechanischen Feder;

Fig. 12

eine schematische Ansicht einer Ausführungsform einer Versorgungseinrichtung zur Druckbeaufschlagung der Innenräume eines Zylinders und/oder mit den Innenräumen jeweils verbundenen Zusatzvolumina mit einem voreinstellbaren, insbesondere veränderbaren, Fluiddruck;

Fig. 13

eine schematische Ansicht einer weiteren Ausführungsform einer Versorgungseinrichtung;

Fig. 14

eine schematische Ansicht einer weiteren Ausführungsform einer Versorgungseinrichtung;

Fig. 15 bis 18

schematische Darstellungen für Beispiele eines Verlaufs von Brems- und/oder Beschleunigungskräften in Abhängigkeit der Drehlage des Werkstücks; und

Fig. 19

eine schematische Darstellung des Verlaufs des an einer Drehantriebseinrichtung der Vorrichtung anliegenden Antriebsmoments ohne und mit Verwendung einer Kraftbeaufschlagungseinrichtung.

In the drawings show:

Fig. 1

a perspective view of an embodiment of a device for finely finishing a workpiece;

Fig. 2

a side view of a portion of the device according to Fig. 1 comprising a finishing tool in the form of a finishing tool, a pressing device and a bearing device;

Fig. 3

one of the Fig. 2 corresponding side view in a broken in the field of Kraftbeaufschlagungseinrichtung representation in a 0 ° corresponding initial position of a workpiece peripheral surface of a workpiece;

Fig. 4

one of the Fig. 3 corresponding side view in a rotated by 90 ° relative to the starting position of the workpiece;

Fig. 5

one of the Fig. 3 corresponding side view in a rotated by 180 ° relative to the starting position of the workpiece;

Fig. 6

one of the Fig. 3 corresponding side view in a rotated by 270 ° relative to the starting position of the workpiece;

Fig. 7

one of the Fig. 3 corresponding side view upon extension of the device with a device for detecting the position of a bearing part of the bearing device;

Fig. 8

one of the Fig. 3 corresponding side view when using mechanical springs as force generating elements and energy storage;

Fig. 9

one of the Fig. 3 corresponding side view when using associated with cylinder / piston units fluidly effective additional volumes;

Fig. 10

one of the Fig. 3 corresponding side view when using a hydraulically controlled gas spring;

Fig. 11

one of the Fig. 3 corresponding side view when using a hydraulically controlled mechanical spring;

Fig. 12

a schematic view of an embodiment of a supply device for pressurizing the interior of a cylinder and / or with the inner spaces respectively associated additional volumes with a presettable, in particular variable, fluid pressure;

Fig. 13

a schematic view of another embodiment of a supply device;

Fig. 14

a schematic view of another embodiment of a supply device;

15 to 18

schematic representations of examples of a course of braking and / or acceleration forces as a function of the rotational position of the workpiece; and

Fig. 19

a schematic representation of the course of the voltage applied to a rotary drive device of the device drive torque without and with the use of a Kraftbeaufschlagungseinrichtung.

An embodiment of a device, designated overall by the reference numeral 10, is used for fine machining, in particular for finish machining, of a workpiece 12. The device 10 comprises a stationary frame 14 with a frame part 16 for connecting a bearing device 18 explained in more detail below to the frame 14. The bearing device 18 serves to support a subsequently explained in more detail pressing device 20 on the frame 14. The pressing device 20 presses a finishing tool in the form of a finishing tool 22 (see FIG. 2 ), for example in the form of a finishing tape, against a surface finish of the workpiece 12 to be machined. The finishing tape is guided on a finishing tape guide 23, for example in the form of a deflection roller 25.

The device 10 comprises a rotary drive device 24 (cf. FIG. 1 ) for rotating the workpiece 12 about a workpiece axis 26 (see FIG FIG. 2 ). The rotary drive device 24 comprises a headstock 28 and a tailstock 30. The workpiece 12 is clamped between the headstock 28 and the tailstock 30. The composite of rotary drive device 24 and workpiece 12 is reciprocally reciprocatable by means of an oscillation drive 32 along an oscillation axis 34 parallel to the workpiece axis 26.

Advantageously, the oscillation drive 32 comprises a carrier 36 for attachment of the headstock 28 and of the tailstock 30. The carrier 36 is driven by means of a known per se and therefore not further explained drive means, for example in the form of an eccentric drive.

The workpiece 12 has a workpiece peripheral surface 38, which is offset eccentrically to the workpiece axis 26. In particular, the workpiece circumferential surface 38 extends concentrically around an additional axis 40, which runs parallel and spaced from the workpiece axis 26.

The workpiece 12 is in particular a crankshaft. The workpiece peripheral surface 38 is, in particular, the bearing surface of a crank bearing of the crankshaft.

During the machining of the workpiece 12, this rotates about the workpiece axis 26. In this case, the workpiece peripheral surface 38 moves the distance of the axes 40 and 26 corresponding circular around the workpiece axis 26. The above-described rotational movement is by means of the oscillation drive 32 in FIG. 1 Superimposed with an oscillating movement indicated by a double arrow 42 in order to provide the workpiece peripheral surface 38 with a cross-cut structure under abrasive action of the finishing tool 22.

Since the workpiece peripheral surface 38 moves around the workpiece axis 26 in a circular manner as explained above, it is also necessary for the finishing tool 22 (optionally together with the tape guide 23) and thus the pressing device 20 to follow this movement of the workpiece peripheral surface 38. Therefore, the bearing means 18 for supporting the pressing device 20 on the frame 14 on two degrees of freedom, which a Movement of the pressing device 20 allows within a plane perpendicular to the workpiece axis 26 level.

The bearing device 18 comprises a pivoting part 44, which is held by means of a pivot bearing 46 about a pivot axis 48 pivotally mounted on the frame part 16. The pivot axis 48 extends parallel to the workpiece axis 26.

The pivoting part 44 serves to arrange at least one linear guide 50, by means of which a bearing part 52 is mounted so as to be displaceable relative to the pivoting part 44 along a guide axis 54 of the linear guide 50.

The bearing part 52 extends substantially within a plane perpendicular to the workpiece axis 26 extending plane. The bearing part 52 has an opening 56 which is penetrated by the pivot bearing 46.

The bearing part 52 has a workpiece end 12 facing the bearing end 58 for the arrangement of the pressing device 20.

The pressing device 20 comprises at least one pressing element 60, preferably two pressing elements 60, which is or are formed, for example, in the form of pliers arms 62. The pliers arms 62 are pivotable about Andrückschwenkachsen 64 relative to the bearing part 52. The pressing pivot axes 64 extend parallel to the pivot axis 48 of the pivoting part 44.

The pliers arms 62 have at their end facing the workpiece 12 Andrückabschnitte 66, which are in particular cup-shaped, so that designed as a finishing belt finishing tool 22 along a Part circumference of the workpiece peripheral surface 38 can be pressed against them.

To generate a pressing force, the pressing device 20 comprises a pressing drive 68, which acts on the pressing elements 60 with a pressing force. The pressure drive 68 is designed, for example, in the form of a hydraulic unit 70, which acts on the pressure elements 60 with pressure forces 72.

For example, the pressing drive 68 and the pressing portions 66 are arranged on sides of the pressing elements 60 facing away from each other with respect to the pressing pivot axes 64. In this way, pressing forces 72 facing away from one another can be redirected into mutually facing pressing forces 74.

The device 10 comprises a force acting between the pivot member 44 and the bearing part 52 force application device 76 (see FIG. 3 ). The force application device 76 generates braking and acceleration forces which act on the bearing part 52 in parallel to the guide axes 54 of the linear guides 50.

The force application device 76 comprises at least one cylinder / piston unit 78, for example two cylinder / piston units 78 arranged parallel to one another. The units 78 each comprise a piston 80, which is immovably connected to the bearing part 52 via a piston rod 82.

The pistons 80 are slidably mounted in fixedly connected to the pivot member 44 cylinders 84. The pistons 80 divide the cylinders 84 into separate ones Interiors, namely a first interior space 86 and a second interior space 88.

The interior spaces 86, 88 are each filled with a pressurized gas and each form in opposite directions rechargeable and dischargeable energy storage 90th

In FIG. 3 the workpiece 12 is shown in a starting position in which the workpiece peripheral surface 38 is located in a "12 o'clock position" relative to the workpiece axis 26. This initial position of the workpiece 12 is hereinafter referred to as "0 °". By rotation of the workpiece 12 about the workpiece axis 26 by means of the rotary drive means 24, for example in a clockwise direction, the workpiece 12, starting from the in FIG. 3 rotated position shown, for example, in a relative to the starting position rotated by 90 ° position (see FIG. 4 ).

As a result of the positive locking acting between the pressing portions 66 and the workpiece circumferential surface 38, the pressing device 20 moves downwards in the vertical direction and simultaneously away from the workpiece axis 26 in the horizontal direction in the course of the rotation of the workpiece 12. The horizontal movement of the pressing device 20 causes a corresponding horizontal displacement of the bearing part 52 relative to the pivot member 44. The vertical movement of the pressing device 20 causes a pivoting of the bearing part 52 and the pivot member 44 about the pivot axis 48th

Due to the horizontal displacement of the bearing part 52, the position of the piston 80 changes relative to the Cylinders 84. In particular, the gas present in the second internal spaces 88 is compressed, so that during the movement of the bearing part 52 from the starting position (FIG. FIG. 3 ) in the in FIG. 4 shown liner increasingly higher braking forces act on the bearing part 52. These braking forces are in the in FIG. 4 shown, fully compressed position of the second interior spaces 88 maximum. Starting from this position causes a further rotation of the workpiece 12 about the workpiece axis 26, an enlargement of the second interior spaces 88, to a in FIG. 5 illustrated intermediate position ("180 °"), the interiors 86 and 88 are each the same size again. During the movement from the intermediate layer "90 °" into the intermediate layer "180 °", the energy stores 90 are unloaded in the form of the second internal spaces 88, so that the bearing part 52 is acted upon by acceleration forces directed onto the workpiece 12.

In FIG. 5 an intermediate layer of the bearing part 52 is shown. FIG. 4 shows a first reversal position of the bearing part 52; FIG. 6 shows a second reversal position of the bearing part 52nd

Starting from the in FIG. 5 shown intermediate position, the bearing member 52 moves upon transfer of the workpiece 12 from the position "180 °" in the position "270 °" (see FIG. 6 ). This movement of the bearing part 52 is accompanied by a compression of the first inner spaces 86, which exert increasingly stronger braking forces on the bearing part 52. The concomitant charging of the first internal spaces 86 is used, in the transition of the workpiece from the position "270 °" back to the starting position "0 °" (ie upon transfer of the workpiece 12 from the in FIG. 6 in the in FIG. 3 shown rotational position) by discharging the / Energy storage 90 in the form of the first internal spaces 86 to exert acceleration forces on the bearing part 52.

In a development of the device 10, a device 92 for detecting the position of the bearing part 52 relative to the pivoting part 44 is provided (see FIG FIG. 7 ). The device 92 has a first holding section 94 connected to the pivoting part 44 for holding a displacement sensor 95. The device also has a second holding part 96 connected to the bearing part 52 for holding a measuring section 98. The position sensor 95 serves to detect a movement of the measuring section 98 and thus to detect the position of the bearing part 52 relative to the pivot part 44. This position detection is advantageous for a control of the force application devices 76 described below.

At an in FIG. 8 In the embodiment shown, a force-applying device 76 with cylinder / piston units 78 is likewise provided. In this embodiment, the energy storage devices 90 are designed in the form of mechanically effective spring elements 100. The operation of this particularly simple constructed Kraftbeaufschlagungseinrichtung 76 according to FIG. 8 corresponds to the operation of the above with reference to FIGS. 3 to 6 described Kraftbeaufschlagungseinrichtung 76th

At an in FIG. 9 In the embodiment shown, a force-applying device 76 with cylinder / piston units 78 is likewise provided. The first interior spaces 86 and the second interior spaces 88 of the units 78 are each connected via lines 102 with additional volumes 104. The additional volumes 104 serve to receive pressurized fluid, in particular gas, which as energy storage 90 is effective. By adjusting the pressure of the gas contained in the additional volume 104 and / or by adjusting the size of the additional volumes for a given amount of gas, a spring rate of the force application device is adjustable, with higher pressures causing a steeper spring characteristic. The basic mode of operation of the force application device 76 according to FIG FIG. 9 corresponds to the operation of the above with reference to FIGS. 3 to 6 described Kraftbeaufschlagungseinrichtung 76th

In the in the Figures 10 and 11 illustrated embodiments are also provided cylinder / piston units 78, the interiors 86, 88 are each connected via lines 102 with additional volumes 104.

The interior spaces 86, 88, the lines 102 and the additional volumes are preferably filled with a liquid. This arrangement has the advantage that the fluid can be used for power transmission in an area outside of the bearing part 52. Therefore, particularly compact cylinder / piston units 78 can be used.

The additional volumes 104 are produced by means of a closure element 106 in the form of a membrane ( FIG. 10 ) or in the form of a piston 108 (FIG. FIG. 11 ) completed. The terminating elements 106, 108 are provided with energy stores 90 in the form of pneumatically active springs 110 (FIG. FIG. 10 ) and / or mechanically effective springs 100 ( FIG. 11 ).

In a movement of the bearing part 52 of the embodiments according to FIG. 10 or 11, the additional volumes 104 are alternately filled alternately or the spring elements 100, 110 alternately compressed, so that they are charged as energy storage 90 alternately and discharged. Otherwise, the mode of operation of the force application device 76 corresponds to FIG FIG. 10 and Figure 11 of the operation of the above with reference to FIGS. 3 to 6 described Kraftbeaufschlagungseinrichtung 76th

In FIG. 12 a supply device 112 for supplying the interior spaces 86, 88 of the units 78 and possibly existing additional volumes 104 is shown with pressurized fluid. The supply device 112 comprises a pressure source 114 (for example a compressed air supply), which communicates via proportional valves 116 and check valves 118 with the interior spaces 86, 88 and the optional additional volumes 104.

The proportional valves 116 are controlled, for example by means of electromagnets. For an increase in the pressure in the respective inner chambers 86, 88, an opening triggering of the proportional valves 116 is sufficient. If pressure is to be reduced in the inner chambers 86, 88, an additional valve 120 is actuated, which exerts a control pressure on the check valves 118, so that the pressure can be reduced in the interior spaces 86, 88 and optionally in the additional volumes 104.

In the in the Figures 13 and 14 illustrated embodiments of utilities 112 communicates a pressure supply 114 via a 4/3-way valve 122 with the different internal spaces 86, 88 of the units 78. In the in FIG. 13 shown Switch position corresponds to the operation of the force application device 76 of the operation of the above with reference to FIGS. 3 to 6 In the two remaining switching positions of the 4/3-way valve 122, the pressure supply 114 can selectively be fluidly connected either to the first interior spaces 86 of the units 78 or to the second interior spaces 88 of the units 78, so that by means of Kraftbeaufschlagungseinrichtung 76 generated braking and / or acceleration forces are selectively changed.

In an advantageous embodiment according to FIG. 14 a control device 124 is provided, which is coupled to the device 92 for detecting the position of the bearing part 52 relative to the pivot part 44 and depending on the position of the bearing part 52, the 4/3-way valve 122 drives.

Such control allows, for example, in the FIGS. 15 to 18 To generate shown force curves. For example, the pressure supply 114 is connected to the second internal spaces 88 by switching the valve 122 at a workpiece position "90 °" and to the first internal spaces 86 at a workpiece position "270 °".

When using a simple switching valve for the valve 122, for example, in FIG. 15 shown force curve can be generated. For example, a connection of the pressure supply 114 with the second inner chambers 88 over a period of time 126 causes a force profile section 128, that is to say along the guide axis 54 of the linear guide 50, a leftward acceleration force. In a corresponding manner causes a connection of the pressure supply 114 with the first Indoors 86 over a period of time 130 a force profile section 132, ie along the guide axis 54 of the linear guide 50 seen a rightward acceleration force.

When using a proportional valve for the valve 122 are also in the FIGS. 16 to 18 shown force curves with steeper rise to a maximum force ( FIG. 16 ) or flatter rise to a maximum force ( FIG. 17 ) possible. It is understood that the force maxima do not necessarily have to be exerted in the area of the workpiece positions "90 °" and "270 °", that is to say in the reversal positions of the bearing part 52. It is also an angle-shifted exercise of forces possible, cf. FIG. 18 ,

The device according to the invention makes it possible to even out the drive torque provided for the rotary drive of the workpiece 12 by the rotary drive device 24. In FIG. 19 the time profiles of drive torques of the rotary drive device 24 are shown. These curves fluctuate sinusoidally between maximum and minimum values. In this case, a complete sinusoidal oscillation corresponds to a single revolution of a workpiece 12 about its workpiece axis 26. Without the use of a force application device 76, a drive torque curve 134 fluctuates considerably more than when using a force application device 76, by means of which a significantly more uniform, ideally even approximately constant drive torque curve 136 is achieved.

Claims (18)

1. A device (10) for the precision machining of a peripheral workpiece surface (38) arranged eccentrically related to a workpiece axis (26) of a workpiece (12), in particular that of a pin bearing of a crankshaft, with its rotary drive device (24) for the rotary drive of a workpiece (12) about the workpiece axis (26), with a pressing unit (20) for pressing a precision machining tool against the peripheral workpiece surface (38) and with a mounting device (18) for mounting the pressing unit (20) on a frame (14), characterised in that a force application device (76) is provided which exerts braking and/or acceleration forces on the bearing part (52) of the mounting device (18) that moves backwards and forwards between two reversible positions due to the rotation of the workpiece (12).
2. The device (10) according to Claim 1, characterised in that, in at least in one of the reversible positions of the bearing part (52), the force application device (76) exerts an acceleration force on the bearing part that is directed in the direction of the other reversible position.
3. The device (10) according to any one of the preceding claims, characterised in that, in at least each of the two reversible positions of the bearing part (52), the force application device (76) exerts an acceleration force on the bearing part (52) that is directed in the direction of the other reversible position.
4. The device (10), according to any of the preceding claims, characterised in that the force application device (76) loads the bearing part (52) with braking and/or acceleration forces when the bearing part (52) is in an intermediate position arranged between the reversible positions.
5. The device (10) according to any one of the preceding claims, characterised in that the force application device (76) has an energy storage device (90) which can be loaded in the curse of the movement of the bearing part (52) from a first reversible position to a second reversible position, and can be unloaded in the opposite direction.
6. The device (10) according to Claim 5, characterised in that the energy storage device (90) comprises mechanically or pneumatically operating spring elements (100, 110).
7. The device (10) according to any one of the preceding claims, characterised in that the force application device (76) comprises at least one cylinder/piston unit (78).
8. The device (10) according to Claim 7, characterised that the interior space (86, 88) of a cylinder (84) of the cylinder/piston unit (78) is connected in a fluidly active manner to an additional volume (104).
9. The device (10) according to Claim 7 or 8, characterised by a supply device (112) for pressurising the inner space (86, 88) of a cylinder (84) and/or an additional volume (104) connected to the inner space (86, 88), with a presettable, in particular variable fluid pressure.
10. The device (10) according to any one of the preceding claims, characterised by a control device (124) for controlling the amount and/or the direction and/or the development in time of the braking and/or acceleration forces acting on the bearing part (52).
11. The device (10) according to any one of the preceding claims, characterised by a device (92) for recording the position of the bearing part (52).
12. The device (10) according to any one of the preceding claims, characterised in that the bearing part (52) is guided on a linear guide (50).
13. The device (10) according to Claim 12, characterised in that the linear guide (50) is swivelled by means of a swivel part (44) relative to the frame (14).
14. The device (10) according to Claim 12 or 13, characterised in that the linear guide (50) is arranged on a slide which is mounted displaceably on the frame (14) in a direction transverse, and in particular perpendicular, to the guide axis (54) of the linear guide (50).
15. The device (10) according to Claim 13 or 14, characterised in that a further force application device is provided to compensate for quantity related forces of inertia which are generated due to a movement of the bearing part (52) about a swivel axis (48) and/or due to the movement of the bearing part (52) in a direction transverse to the guide axis (54) of the linear guide (50).
16. The device (10) according to any one of the preceding claims, characterised in that the bearing part (52) is moveable along an axis that is vertical in relation to the direction of the force of gravity, in that a compensating device is provided which generates at least proportionately a retention force acting vertically upwards, which force, in terms of quantity, is equal to the effective weight of the pressing device (20), the bearing part (52) and the precision machining tool, and/or in that the force application device (76) at least proportionately generates such a retention force.
17. The device (10) according to any one of the preceding claims, characterised in that the precision machining tool is a finishing tool (22) for the finish machining of the circumferential workpiece surface (38).
18. The device (10) according to any one of the preceding claims, characterised by an oscillation drive (32) for loading the workpiece (12) with an oscillation movement parallel with the workpiece axis (26).

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